Thin wall fitment for spouted pouch

ABSTRACT

A fitment has walls with a spout aperture therebetween. Reduced wall thickness results in a reduced amount of plastic in the fitment. An alternative embodiment uses radially extending meltable fins. During installation in a sealing apparatus, a heated mandrel engages the inner diameter of the spout aperture thereby pre-heating and physically supporting the fitment during the installation process. The heated mandrel typically engages the fitment at least one cycle prior to be installed. The fitment may be canoe-shaped.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.09/643,033, filed on Aug. 21, 2000, no U.S. Pat. No. 6,612,466, issuedon Sep. 2, 2003 the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to a fitment for a spouted pouch, particularlyone with a canoe-type base or meltable fin wherein the plastic isreduced in transition areas and in the wall thickness of the base. Toaccelerate and maintain the integrity of the process for installing afitment, a heated mandrel shaped and sized to the inner diameter of thefitment passageway is used.

2. Description of the Prior Art

In the prior art, it is known to use a fitment/spout with a canoe shapedbase with extended meltable fins oriented 180° apart, and multiplehorizontal ribs spaced evenly across the height of the canoe. The canoeshape and the meltable fins assure gradual transition from the two pliesof film (one on each side of the fitment) to the maximum width of thecanoe in the diametrical center of the fitment.

In order to seal or weld the fitments to the film at the fastestpossible rate, and to reduce potential leaking at the base, the base canbe made with horizontal ribs to increase the sealing pressure and toreduce the dwell time. However, the sealing pressure must not damage ormisshape the inner diameter of the fitment. To avoid such problems, thecanoe base is typically made more massive than would otherwise berequired.

Because the maximum temperature of the jaws is limited by thecharacteristics of the film, the two driving variables of the sealingequation become the dwell time and the pressure. That is, a canoe basewhich is enlarged for the above reasons requires increased dwell timeand pressure to bring it to the sealing temperature, which iscounterproductive to the production rates of the fitment attachmentprocess.

The attachment of this kind of fitment is disclosed in U.S. patentapplication Ser. No. 09/452,714 entitled “Method for Attaching Fitmentat Longitudinal Fin Seal and Package Resulting Therefrom” filed on Dec.2, 1999.

Other prior art includes U.S. Pat. No. 5,911,340 entitled “SpoutAssembly, Spout Assembly Manufacturing Apparatus and Package with SpoutAssembly” issued on Jun. 15, 1999 to Uematsu; U.S. Pat. No. 5,716,471entitled “Method for Securing Articles to Laminates” issued on Feb. 10,1998 to Pape; U.S. Pat. No. 4,909,434 entitled “Moisture ImperviousCarton Having One-Piece Pouring Spout Sealed to Innermost and OutermostSurfaces” issued on Mar. 20, 1990 to Jones et al.; and U.S. Pat. No.3,894,381 entitled “Method and Means for Attaching Fitments to a Bag orPouch on a Packaging Machine” issued on Jul. 15, 1975 to Christine etal.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a fitmentwith canoe-shaped walls which can be installed between two plies ofplastic film with reduced dwell time and/or reduced jaw pressure.

It is therefore a further object of the present invention to provide afitment with canoe-shaped walls which can be installed at high speeds.

It is therefore a still further object of the present invention toprovide a fitment with canoe-shaped walls which can reliably maintainits shape during installation.

These and other objects are attained by providing an injection moldedfitment with reduced plastic in the canoe base, to retain the shape andlength of the canoe, but to reduce the amount of plastic in transitionareas and in the wall thickness of the base. This reduces the mass ofthe canoe and the required preheat/sealing dwell time. An alternativeembodiment employs radially extending meltable fins in place of thecanoe base. In order to compensate for the reduction in the rigidity ofthe base and the resulting reduction in ability to withstand thepressure of the sealing bars, the fitment is installed with a heatedmandrel inserted through the inner diameter of the fitment. Morespecifically, as the fitment travels along the track from the vibratorybowl to the sealing station, a heated mandrel shaped and sized to theinner diameter of the fitment is inserted into the inner diameter of thefitment. In order to avoid unnecessary softening of the fitment, thetemperature of the mandrel is typically 20–30° F. below the softeningtemperature of the resin from which the fitment is molded. In order toheat the fitment thoroughly from the inside prior to installationwithout slowing down the installation process, the mandrel is typicallyinserted at least one cycle away from the sealing position. Theinsertion of the heated mandrel into the inside diameter of the fitmentwill further prevent the collapse or misshaping of the base. Indeed, thesealing dwell time is thereby reduced by both the reduction of plasticin the base and the heating of the fitment by the mandrel.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become apparentfrom the following description and claims and from the accompanyingdrawings, wherein:

FIG. 1 is a top plan view of a typical prior art fitment.

FIG. 2 is a side view partially in phantom of the fitment of the presentinvention.

FIG. 3 is a top plan view of the fitment of the present invention.

FIG. 4 is a side plan view, partially in cross-section, of the fitmentof the present invention, shown with the heated mandrel inserted throughthe inner diameter thereof.

FIG. 5 is a top view of the fitment of the present invention as it isbeing sealed to the film panels.

FIG. 6 is a perspective view of an alternative embodiment of the presentinvention wherein meltable fins are substituted for the canoe-shapedbase.

FIG. 7 is a top plan view of the embodiment of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in detail wherein like numerals refer tolike elements throughout the several views, one sees that FIG. 1 is atop plan view of a prior art fitment 200. Fitment 200 includescanoe-shaped walls 202, 204 which join to form pointed ends 206, 208.The shape of walls 202, 204 and pointed ends 206, 208 allows for agradual transition from the two plies of film (not shown, but which aresealed to walls 202, 204) to the maximum width of the canoe in thediametrical center 210 of the fitment 200, wherein spout aperture 212 isformed. Spout aperture 212 passes through a stem (not shown) whichtypically includes an externally threaded structure and a cylindricalflange 214 and further forms spout walls to allow the dispensing ofliquid or near-liquid product from a container formed by two plasticsheets sealed to walls 202, 204. While not shown in FIG. 1, walls 202,204 may include a ribbed structure, with ribs extending from pointed end206 to pointed end 208.

Fitment 10 is typically molded from polyethylene or polypropyleneplastic, although those skilled in the art may recognize that otherequivalents are available.

Fitment 10 of the present invention, as shown in FIG. 2, is envisionedto have an aperture area wall 13 with a thickness in the range of 0.020inches, as compared to a typical prior art value in the range of 0.035to 0.040 inches. Similarly, fitment 10 is envisioned to have verticalsupport walls 14, 16 with a thickness in the range of 0.015 to 0.025inches rather than the typical prior art value of 0.035 to 0.040 inchesand sealing ribs 30,32,34,36 which are 0.025 to 0.030 inches wide ratherthan the typical prior art value of 0.040 to 0.050 inches. Again, thisreduced material allows fitment 10 to be installed with a reducedsealing dwell time.

As shown in FIG. 2, canoe wall 16 (as well as canoe wall 14) includesribs 30, 32, 34, 36 extending between pointed ends 20, 22. Stem 40extends from upper wall 38 and includes external threads 42 andcylindrical stop 44 which interact with an internally threaded cap (notshown) to seal mouth 46 of spout aperture 12 which is formed at the topof stem 40. As shown in FIG. 3, aperture 12 can include an enlargeddiameter area 50 proximate to mouth 46 and inwardly from externalthreads 42.

Fitment 10′, an alternative embodiment of the present invention, isillustrated in FIG. 6. A retaining ring 300 serves as a support forcylindrical skirt 302 on the underside and spout 304 on the upperside.Aperture 12, similar to aperture 12 illustrated in previous drawingsherein, passes through cylindrical skirt 302 and spout 304. Meltablefins 306, 308 extend radially from cylindrical skirt 302.

FIG. 4 illustrates heated mandrel 100 inserted through aperture 12during the installation process. Mandrel 100 is typically heated to20–30° F. below the softening point of the resin.

FIG. 5 illustrates the sealing of the sheets 102, 104 of plastic film tocanoe walls 16, 18 of fitment 10 by sealing jaws 106, 108 of a fitmentsto film sealing apparatus 110. Sealing jaws 106, 108 are heated toperform the sealing operation and have opposing recesses 110, 112 whichform cavity 114 which is complementary in shape to fitment 10 (See FIG.2, 3 or 6).

Thus the several aforementioned objects and advantages are mosteffectively attained. Although a preferred embodiment of the inventionhas been disclosed and described in detail herein,

-   -   it should be understood that this invention is in no sense        limited thereby and its scope is to be determined by that of the        appended claims.

1. The method of securing a fitment to a package including the steps of:providing package wall material including first and second edges of saidmaterial; providing, from a source, said fitment with walls with athickness of less than 0.035 inches; a mandrel through an aperture ofsaid fitment while the mandrel is heated thereby warming said fitment;inserting said fitment between said first and second edges of saidmaterial; closing the outer sealing jaws onto the first and second edgesof said material with said fitment engaged on said heated mandrel; andsealing said fitment to a portion of said first and second edges.
 2. Themethod of securing a fitment of claim 1 wherein said heated mandrelheats said fitment to a temperature between substantially 20–30° F.below a softening point of the material of said fitments.
 3. The methodof claim 1 wherein said fitment has walls with a thickness of less than0.020 inches.